A UAV variable fertilization device and method

Abstract

A variable fertilization device and method for unmanned aerial vehicles belong to the technical field of intelligent agricultural machinery. In the variable fertilization device for unmanned aerial vehicles of the present invention, a fertilizer discharge component is fixedly connected to the unmanned aerial vehicle through its upper fertilizer box, and is fixedly connected to the fertilizer spreading component through its lower fertilizer discharge hole. The fertilizer discharge component adopts a symmetrically arranged double outer groove wheel type fertilizer discharge structure, and the fertilizer spreading component adopts a double spiral wheel type fertilizer spreading structure. By connecting the servo controller input end of the motor with the flight control system output end of the unmanned aerial vehicle, combined with the global positioning system, geographic information system and fertilizer prescription map information, variable fertilization control of the unmanned aerial vehicle is realized; the present invention can realize high-precision variable fertilization operation of the unmanned aerial vehicle, the fertilizer discharge stability is good, and the method has universality.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent agricultural machinery, and in particular relates to an unmanned aerial vehicle variable fertilization device and method. Background Art

[0002] With the deepening of research in the field of agricultural technology, agriculture has begun to develop towards green and precision. The country has proposed a policy of reducing both fertilizer and pesticide, and promoted the spraying of fertilizers and pesticides to be precise and quantitative. Agricultural drones, as an emerging technology in recent years, are being widely promoted and applied. Compared with large-scale fertilizer applicators on the ground, the use of drones equipped with special spreading devices for fertilization has more obvious advantages. Especially in wetland crop planting areas, large-scale fertilizer machinery on the ground is difficult to go to the ground for fertilization operations and the operation efficiency is not high. In addition, if farmers rely solely on experience to carry out manual fertilization, it is not only time-consuming and laborious, but also cannot guarantee the uniformity of fertilization in the fertilization area. In contrast, the efficiency of fertilizing large areas of farmland using drones is much higher than that of ground operation machinery and manual operations.

[0003] Traditional fertilization drones often spread fertilizer evenly over the entire operating area. This method of fertilization cannot ensure that all the land gets enough fertilizer, and some areas will have excess fertilizer, leading to the abuse and waste of fertilizer. At present, in terms of the method of using drones for fertilization, variable fertilization can be achieved by changing the speed of the slot wheel fertilizer discharge device, increasing the opening size of the drop port, etc. However, the existing external slot wheel fertilizer discharger has the problem of poor fertilizer discharge stability, and the fertilizer will be subject to greater pulsation, which in turn affects the fertilizer discharge accuracy. Therefore, it is necessary to conduct research on a high-stability variable fertilization device suitable for drone fertilization operations. Summary of the invention

[0004] The purpose of the present invention is to provide a UAV variable fertilization device and method to solve the problem that the existing external groove wheel fertilizer discharger has low fertilizer discharge stability and affects the accuracy of variable fertilization operations, and to provide a more intelligent, efficient and accurate UAV variable fertilization operation device and method.

[0005] The variable fertilizer application device of the present invention is composed of a mechanical structure part A, a UAV fertilizer control system B and a variable fertilizer expert system C, wherein the mechanical structure part A is composed of a UAV D, a battery assembly E, a variable fertilizer controller F, a support rod assembly I, a fertilizer discharge component G, a fertilizer spreading component H and a support plate assembly J. The UAV D adopts a commercially available six-rotor electric UAV, the battery assembly E is fixedly connected to the top of the UAV D, the variable fertilizer controller F is fixedly connected to the middle of the UAV D to receive the signal of the UAV fertilizer control system, the support rod assembly I is fixedly connected to the bottom of the UAV D, and the fertilizer discharge component G is composed of a fertilizer box cover 1, a fertilizer box 2, a fertilizer discharge port 3, a fertilizer baffle plate I4, a fertilizer baffle plate II5, a groove wheel I6, a groove wheel II7, and a fertilizer box side plate. 8, guide plate 9, fertilizer transport plate 10 and fertilizer transmission mechanism K, wherein: the fertilizer transmission mechanism K is composed of a secondary gear I 22, a worm wheel I 23, a worm 24, a worm wheel II 25, a secondary gear II 26, a groove wheel shaft I 27, a Hall element I 28, a servo motor I 29, a fixed frame 30, a groove wheel shaft II 31, a mounting shell 32, a worm wheel I shaft 33, a worm wheel II shaft 34 and a servo controller IM. The servo motor I 29 is fixedly connected to the middle position of the lower part of the fixed frame 30 of the mounting shell 32, the output shaft of the servo motor I 29 is fixedly connected to the lower end of the worm 24, the servo controller IM is fixedly connected below the servo motor I 29, and the input end of the servo controller IM is connected to the output end of the variable fertilizer controller F of the drone D to ensure The speed of the servo motor I is sensitively controlled, and the Hall element I28 is fixed to the lower end of the worm 24 so as to obtain the worm speed in real time; the secondary gear I22, the worm wheel I23, the worm 24, the worm wheel II25 and the secondary gear II26 are arranged in sequence from right to left, and the centers of the secondary gear I22, the worm wheel I23, the worm wheel II25 and the secondary gear II26 are on the same straight line, and the right side of the worm 24 is meshed with the secondary gear I22 through the worm wheel I23; the left side of the worm 24 is meshed with the secondary gear II26 through the worm wheel II25; the secondary gear I22 is fixed to the rear side of the groove wheel shaft II31, the secondary gear II26 is fixed to the rear side of the groove wheel shaft I27, the worm wheel I23 is fixed to the worm wheel I shaft 33, the worm wheel II25 is fixed to the worm wheel II shaft 34, and the groove wheel shaft The rear ends of shaft Ⅰ27 and groove wheel shaft Ⅱ31 are movably hinged with the mounting shell 32, and the rear ends of worm wheel Ⅰ shaft 33 and worm wheel Ⅱ shaft 34 are movably hinged with the mounting shell 32; and it is ensured that worm wheel Ⅰ23 and worm wheel Ⅱ25, secondary gear Ⅰ22 and secondary gear Ⅱ26 rotate in opposite directions at the same speed during rotation; the fertilizer box cover 1, fertilizer box 2 and fertilizer discharge port 3 are arranged and fixed from top to bottom, the center of the fertilizer discharge port 3 coincides with the center of the lower end surface of the fertilizer box 2, the guide plate 9 is an inverted V-shaped structure, and the rear end surface of the guide plate 9 is fixed to the front of the rear side plate of the lower part of the fertilizer box 2, and satisfies α≤β≤1.5α, wherein β is the angle between the hypotenuse of the guide plate and the horizontal direction; α is the repose angle of the fertilizer pile, which is generally 30°-40°, to ensure that the fertilizer falls in an orderly manner without being blocked on the upper surface of the guide plate 9.

[0006] The fertilizer baffle I 4 and the fertilizer baffle II 5 are symmetrically and fixedly connected to the inner sides of the left and right side plates at the lower part of the fertilizer box 2, and the included angle δ between the center line connections of the fertilizer baffle I 4 and the fertilizer baffle II 5 satisfies δ > π - 2α, so as to ensure that the fertilizer does not accumulate on the fertilizer baffle I 4 and the fertilizer baffle II 5 during the transportation process by the fluted roller I 6 and the fluted roller II 7.

[0007] The fertilizer conveyor plate 10 is of a conical structure, its upper end is fixedly connected to the inner wall of the upper part of the fertilizer box 2, and the cone angle θ satisfies 180° - 2β < θ < 180° - β. The diameter d of the blanking port at the lower end of the fertilizer conveyor plate 10 satisfies R < d < 2R, where R is the radius of the fluted roller I 6 and the fluted roller II 7. The distance h between the lower end of the fertilizer conveyor plate 10 and the upper end of the diversion plate 9 satisfies 0.7R < h < R. The fertilizer box side cover 8, the fluted roller I 6 and the fluted roller II 7, the fertilizer box 2, and the fertilizer discharging transmission mechanism K are arranged in sequence from front to back. Among them, the fertilizer box side cover 8 is fixedly connected to the front surface of the lower part of the fertilizer box 2 by bolts. The fluted roller I 6 and the fluted roller II 7 have the same structure, and there are 8 protrusions in the protrusion group (a) and 8 grooves in the groove group (b) on their circumferences, and each protrusion and groove are arranged at intervals. The fluted roller I 6 and the fluted roller II 7 are symmetrically placed on the left and right in the lower cavity of the fertilizer box 2. The fluted roller I 6 is fixedly connected to the front end of the fluted roller shaft I 27 of the fertilizer discharging transmission mechanism K. The fluted roller II 7 is fixedly connected to the front end of the fluted roller shaft II 31 of the fertilizer discharging transmission mechanism K. The fluted roller I 6 and the fluted roller II 7 move in opposite directions at the same speed. At the initial moment, the center line of the groove of the fluted roller I 6 coincides with the center line of the protrusion of the fluted roller II 7 along the horizontal direction. The center distance L between the centers of the fluted roller I 6 and the fluted roller II 7 satisfies: 3.5R - 1.5r < L < 4R - 2r, where: R is the radius of the fluted roller, and r is the distance between the lowest point of the groove and the center of the fluted roller, so as to ensure that the fertilizer does not affect the fertilizer discharging accuracy due to collision with the opposite blanking or the fluted roller when the fertilizer freely falls during the transportation process of the fluted roller I 6 and the fluted roller II 7. The installation shell 32 of the fertilizer discharging transmission mechanism K is fixedly connected to the rear side plate of the lower part of the fertilizer box 2 by bolts.

[0008] The fertilizer spreading component H is composed of a feed port 11, a spiral fertilizer wheel Ⅰ12, an end cover 13, a discharge port 14, an ultrasonic sensor 15, an outer shell 16, a bearing Ⅰ18, a bearing Ⅱ19, a spiral fertilizer wheel Ⅱ20 and a fertilizer spreading transmission mechanism L, wherein: the fertilizer spreading transmission mechanism L is composed of a transmission gear Ⅰ17, a transmission gear Ⅱ21, a transmission gear shaft Ⅰ35, a driving gear 36, a Hall element Ⅱ37, a servo motor Ⅱ38, a motor output shaft 39, a transmission gear shaft Ⅱ40 and a servo controller ⅡN, and the upper end of the output shaft 39 of the servo motor Ⅱ38 The servo controller ⅡN is fixedly connected to the driving gear 36, and the servo controller ⅡN is fixedly connected to the bottom of the servo motor Ⅱ38. The input end of the servo controller ⅡN is connected to the output end of the variable fertilizer controller F of the drone D to ensure sensitive control of the speed of the servo motor Ⅱ. The Hall element Ⅱ37 is fixedly connected to the front end of the motor output shaft 39 to obtain the motor output speed in real time; the transmission gear Ⅰ17, the driving gear 36 and the transmission gear Ⅱ21 are arranged and meshed from right to left; the center of the transmission gear Ⅰ17 is fixedly connected to the lower end of the transmission gear shaft Ⅱ40, and the center of the transmission gear Ⅱ21 is fixedly connected to the transmission gear shaft Ⅱ40. The lower end of the shaft Ⅰ35 is fixed; the feed port 11 is arranged at the front upper part of the outer shell 16, the discharge port 14 is arranged at the rear lower part of the outer shell 16, and the discharge port 14 adopts a circular ring transition to a conical structure from top to bottom to ensure the uniform spreading of fertilizer, the end cover 13 is fixed to the rear end of the outer shell 16 by bolts, and the ultrasonic sensor 15 is fixed to the inner wall of the discharge port 14 and is located on the transition line between the circular ring and the cone of the inner wall of the discharge port 14 to monitor the real-time discharge of granular fertilizer; the spiral fertilizer wheel Ⅱ20 and the spiral fertilizer wheel Ⅰ12 are symmetrically arranged in the left and right directions inside the outer shell 16; The inner ring of the spiral fertilizer wheel Ⅰ12 is fixedly connected to the outer ring of the transmission gear shaft Ⅱ40 in the fertilizer spreading transmission mechanism L, and the rear end of the transmission gear shaft Ⅱ40 is movably connected to the right part of the end cover 13 via the bearing Ⅰ18; the inner ring of the spiral fertilizer wheel Ⅱ20 is fixedly connected to the outer ring of the transmission gear shaft Ⅰ35 in the fertilizer spreading transmission mechanism L, and the rear end of the transmission gear shaft Ⅰ35 is movably connected to the left part of the end cover 13 via the bearing Ⅱ19; the center distance P between the spiral fertilizer wheel Ⅰ12 and the spiral fertilizer wheel Ⅱ18 satisfies: R1+r1 / 2≤P≤2R1, wherein R1 is the major diameter of the spiral blade, and r1 is the minor diameter of the spiral blade.

[0009] The variable fertilization expert system C is connected to the UAV fertilization control system B through wireless data transmission. The variable fertilization controller F of the mechanical structure part A is controlled by the UAV fertilization control system B. It is connected to the variable fertilization controller F in the mechanical structure part A through wireless data transmission to obtain real-time information such as fertilizer amount and servo motor speed. At the same time, the UAV fertilization control system B can make corresponding responses.

[0010] The outer side of the fertilizer box 2 of the fertilizer discharging component G is symmetrically fixed to the rear side of the drone D along the left-right direction, the outer peripheral surface of the fertilizer discharging port 3 of the fertilizer discharging component G is fixed to the inner peripheral surface of the feeding port 11 of the fertilizer spreading component H, and a gap is left between the lower end of the fertilizer discharging port 3 and the lower edge of the feeding port 11 of the fertilizer spreading component H; the lower end of the outer shell 16 of the fertilizer spreading component H contacts the upper end surface of the support plate 42 of the support plate assembly J, and the servo motor II 38 is placed in the motor mounting frame 43 of the support plate assembly J, and the discharge port 14 of the fertilizer spreading component H is sleeved in the positioning hole 41 of the support plate assembly J; the left and right lower end surfaces of the support plate 42 of the support plate assembly J are respectively fixed to the left and right cross bars of the support rod assembly I.

[0011] The variable fertilization method of the UAV variable fertilization device of the present invention comprises the following steps:

[0012] 1.1 Obtain the location information of the work site through the global positioning system, and draw the site grid in the description in combination with the geographic information system (GIS);

[0013] 1.2 The variable fertilization expert system C combines soil nutrients and target yield information to obtain the fertilizer amount for each grid and generate a fertilization prescription map;

[0014] 1.3 Obtain the target fertilization amount based on the information of the fertilization prescription map, and import the target fertilization amount information into the UAV fertilization control system B;

[0015] 1.4 When the UAV is working in the field, the UAV fertilization control system B determines the location of the UAV according to the positioning system signal, and combines the fertilization prescription information and the flight speed of the UAV to determine the speed of the servo motor I 29 and the servo motor II 38, and further obtains the speed of the groove wheel and the speed of the spiral fertilizer wheel;

[0016] 1.5 The ultrasonic sensor 15 obtains the real-time fertilizer discharge volume, and transmits the real-time fertilizer discharge volume as a feedback signal to the UAV fertilization control system B. The UAV fertilization control system B adjusts the servo motor speed according to the target fertilizer amount to achieve fertilizer amount adjustment, and finally completes variable fertilization in different operation areas.

[0017] The beneficial effects of the present invention are as follows: the fertilizer discharge component and the fertilizer spreading component respectively adopt a double outer groove wheel type and a double spiral wheel type structure and parameter setting to improve the stability of the fertilizer discharge operation, and at the same time cooperate with the flow monitoring sensor to obtain the real-time fertilizer discharge volume in real time to realize feedback control, thereby improving the control accuracy of variable fertilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 .It is a schematic diagram of the structure of the UAV variable fertilization device;

[0019] Figure 2 .It is a schematic diagram of the structure of the mechanical structure part A;

[0020] Figure 3 . It is a schematic diagram of the assembly of the fertilizer discharge component G;

[0021] Figure 4 . It is a partial enlarged view of the fertilizer discharge component G;

[0022] Figure 5 . A schematic diagram of the internal structure of the fertilizer box 2;

[0023] Figure 6 . It is a front view of the fertilizer spreading component H;

[0024] Figure 7 .for Figure 6 Middle AA section view;

[0025] Figure 8 . It is the front view of the fertilizer transmission mechanism K;

[0026] Fig. 9 .Top view of fertilizer discharging transmission mechanism K

[0027] Fig.10 . It is a schematic diagram of the structure of the fertilizer spreading transmission mechanism L;

[0028] Fig.11 . A top view of the structure of the support plate assembly J;

[0029] Fig.12 . Flowchart of the variable fertilization method for UAVs;

[0030] Among them: A. Mechanical structure B. UAV fertilization control system C. Variable fertilization expert system D. UAV E. Battery assembly F. Variable fertilization controller G. Fertilizer discharge component H. Fertilizer spreading component I. Support rod assembly J. Support plate assembly K. Fertilizer discharge transmission mechanism L. Fertilizer spreading transmission mechanism M. Servo controller Ⅰ N. Servo controller Ⅱ 1. Fertilizer box cover 2. Fertilizer box 3. Fertilizer discharge port 4. Fertilizer baffle Ⅰ 5. Fertilizer baffle Ⅱ 6. Groove wheel Ⅰ 7. Groove wheel Ⅱ 8. Fertilizer box side cover 9. Guide plate 10. Fertilizer transport plate 11. Feeding port 12. Spiral fertilizer wheel Ⅰ 13. End cover 14. Discharge port 15. Ultrasonic sensor 16. Outer shell 17. Transmission gear I 18. Bearing I 19. Bearing II 20. Spiral fertilizer wheel II 21. Transmission gear II 22. Secondary gear I 23. Worm wheel I 24. Worm 25. Worm wheel II 26. Secondary gear II 27. Groove wheel shaft I 28. Hall element I 29. Servo motor I 30. Fixed frame 31. Groove wheel shaft II 32. Mounting shell 33. Worm wheel I shaft 34. Worm wheel II shaft 35. Transmission gear shaft I 36. Driving gear 37. Hall element II 38. Servo motor II 39. Output shaft 40. Transmission gear shaft II 41. Positioning hole 42. Support plate 43. Motor mounting frame. DETAILED DESCRIPTION

[0031] The present invention is described below with reference to the accompanying drawings.

[0032] like Figure 1 and Figure 2 As shown, a variable fertilization device for unmanned aerial vehicles of the present invention is composed of a mechanical structure part A, an unmanned aerial vehicle fertilization control system B and a variable fertilization expert system C, wherein the mechanical structure part A is composed of an unmanned aerial vehicle D, a battery assembly E, a variable fertilization controller F, a support rod assembly I, a fertilizer discharge component G, a fertilizer spreading component H and a support plate assembly J. The unmanned aerial vehicle D adopts a commercially available six-rotor electric unmanned aerial vehicle, the battery assembly E is fixedly connected to the top of the unmanned aerial vehicle D, the variable fertilization controller F is fixedly connected to the middle of the unmanned aerial vehicle D to receive the signal of the unmanned aerial vehicle fertilization control system, and the support rod assembly I is fixedly connected to the bottom of the unmanned aerial vehicle D. The variable fertilization expert system C is connected to the unmanned aerial vehicle fertilization control system B through wireless data transmission, the variable fertilization controller F of the mechanical structure part A is controlled by the unmanned aerial vehicle fertilization control system B, and is connected to the variable fertilization controller F in the mechanical structure part A through wireless data transmission, so as to obtain information such as fertilizer amount and servo motor speed in real time, and the unmanned aerial vehicle fertilization control system B can make a corresponding response. The outer side of the fertilizer box 2 of the fertilizer discharging component G is symmetrically fixed to the rear side of the drone D along the left-right direction, the outer peripheral surface of the fertilizer discharging port 3 of the fertilizer discharging component G is fixed to the inner peripheral surface of the feeding port 11 of the fertilizer spreading component H, and a gap is left between the lower end of the fertilizer discharging port 3 and the lower edge of the feeding port 11 of the fertilizer spreading component H; the lower end of the outer shell 16 of the fertilizer spreading component H contacts the upper end surface of the support plate 42 of the support plate assembly J, and the servo motor II 38 is placed in the motor mounting frame 43 of the support plate assembly J, and the discharge port 14 of the fertilizer spreading component H is sleeved in the positioning hole 41 of the support plate assembly J; the left and right lower end surfaces of the support plate 42 of the support plate assembly J are respectively fixed to the left and right cross bars of the support rod assembly I.

[0033] like Figures 3 to 5As shown in the figure, the fertilizer discharging component G consists of a fertilizer box cover 1, a fertilizer box 2, a fertilizer discharging port 3, a fertilizer blocking plate I 4, a fertilizer blocking plate II 5, a grooved pulley I 6, a grooved pulley II 7, a fertilizer box side plate 8, a diversion plate 9, a fertilizer transporting plate 10 and a fertilizer discharging transmission mechanism K. The fertilizer box cover 1, the fertilizer box 2 and the fertilizer discharging port 3 are arranged and fixedly connected from top to bottom. The center of the fertilizer discharging port 3 coincides with the center of the lower end face of the fertilizer box 2. The diversion plate 9 is of an inverted V-shaped structure. The rear end face of the diversion plate 9 is fixedly connected to the front of the rear side plate of the lower part of the fertilizer box 2, and it satisfies that α≤β≤1.5α, where β is the angle between the hypotenuse of the diversion plate and the horizontal direction; α is the angle of repose of the fertilizer heap, generally 30°-40°, to ensure that the fertilizer falls orderly without congestion on the upper surface of the diversion plate 9. The fertilizer blocking plate I 4 and the fertilizer blocking plate II 5 are symmetrically and fixedly connected to the inner sides of the left and right side plates of the lower part of the fertilizer box 2, and it satisfies that the included angle δ between the midline connection lines of the fertilizer blocking plate I 4 and the fertilizer blocking plate II 5 is greater than π - 2α, to ensure that the fertilizer does not accumulate on the fertilizer blocking plate I 4 and the fertilizer blocking plate II 5 during the transportation process by the grooved pulley I 6 and the grooved pulley II 7. The fertilizer transporting plate 10 is of a conical structure. Its upper end is fixedly connected to the inner wall of the upper part of the fertilizer box 2, and the conical angle θ satisfies 180° - 2β < θ < 180° - β. The diameter d of the blanking port at the lower end of the fertilizer transporting plate 10 satisfies R < d < 2R, where R is the radius of the grooved pulley I 6 and the grooved pulley II 7. The distance h between the lower end of the fertilizer transporting plate 10 and the upper end of the diversion plate 9 satisfies 0.7R < h < R. The fertilizer box side cover 8, the grooved pulley I 6 and the grooved pulley II 7, the fertilizer box 2, and the fertilizer discharging transmission mechanism K are arranged in sequence from front to back. Among them, the fertilizer box side cover 8 is fixedly connected to the front of the lower part of the fertilizer box 2 by bolts. The grooved pulley I 6 and the grooved pulley II 7 have the same structure. There are 8 protrusions in the protrusion group (a) and 8 grooves in the groove group (b) on their circumferences, and each protrusion and groove are arranged at intervals. The grooved pulley I 6 and the grooved pulley II 7 are symmetrically placed in the lower cavity of the fertilizer box 2. The grooved pulley I 6 is fixedly connected to the front end of the grooved pulley rotating shaft I 27 of the fertilizer discharging transmission mechanism K. The grooved pulley II 7 is fixedly connected to the front end of the grooved pulley rotating shaft II 31 of the fertilizer discharging transmission mechanism K. The grooved pulley I 6 and the grooved pulley II 7 move in opposite directions at the same speed. At the initial moment, it satisfies that the center line of the groove of the grooved pulley I 6 coincides with the center line of the protrusion of the grooved pulley II 7 along the horizontal direction. The center distance L between the grooved pulley I 6 and the grooved pulley II 7 satisfies: 3.5R - 1.5r < L < 4R - 2r, where: R is the radius of the grooved pulley, and r is the distance between the lowest point of the groove and the center of the grooved pulley, to ensure that the fertilizer does not affect the fertilizer discharging accuracy due to collision with the opposite blanking or the grooved pulley when the fertilizer freely falls during the fertilizer transportation process by the grooved pulley I 6 and the grooved pulley II 7. The installation shell 32 of the fertilizer discharging transmission mechanism K is fixedly connected to the rear side plate of the lower part of the fertilizer box 2 by bolts.

[0034] As Figure 6 to Figure 7As shown, the fertilizer spreading component H is composed of a feed port 11, a spiral fertilizer wheel Ⅰ12, an end cover 13, a discharge port 14, an ultrasonic sensor 15, an outer shell 16, a bearing Ⅰ18, a bearing Ⅱ19, a spiral fertilizer wheel Ⅱ20 and a fertilizer spreading transmission mechanism L. The feed port 11 is arranged at the front upper part of the outer shell 16, and the discharge port 14 is arranged at the rear lower part of the outer shell 16. The discharge port 14 adopts a circular ring transition to a conical structure from top to bottom to ensure uniform spreading of fertilizer. The end cover 13 is fixed to the rear end of the outer shell 16 by bolts. The ultrasonic sensor 15 is fixed to the inner wall of the discharge port 14 and is located on the transition line between the circular ring and the cone of the inner wall of the discharge port 14 to monitor the real-time discharge of granular fertilizer. The outer shell 16 has spiral fertilizer wheel Ⅱ20 and spiral fertilizer wheel Ⅰ12 symmetrically arranged along the left and right directions; the inner ring of spiral fertilizer wheel Ⅰ12 is fixedly connected to the outer ring of transmission gear shaft Ⅱ40 in fertilizer spreading transmission mechanism L, and the rear end of transmission gear shaft Ⅱ40 is movably connected to the right part of end cover 13 via bearing Ⅰ18; the inner ring of spiral fertilizer wheel Ⅱ20 is fixedly connected to the outer ring of transmission gear shaft Ⅰ35 in fertilizer spreading transmission mechanism L, and the rear end of transmission gear shaft Ⅰ35 is movably connected to the left part of end cover 13 via bearing Ⅱ19; the center distance between spiral fertilizer wheel Ⅰ12 and spiral fertilizer wheel Ⅱ18 is P, which satisfies: R1+r1 / 2≤P≤2R1, where R1 is the major diameter of the spiral blade and r1 is the minor diameter of the spiral blade.

[0035] like Figure 8 and Fig. 9As shown, the fertilizer transmission mechanism K is composed of a secondary gear Ⅰ22, a worm wheel Ⅰ23, a worm 24, a worm wheel Ⅱ25, a secondary gear Ⅱ26, a grooved wheel shaft Ⅰ27, a Hall element Ⅰ28, a servo motor Ⅰ29, a fixed frame 30, a grooved wheel shaft Ⅱ31, a mounting shell 32, a worm wheel Ⅰ shaft 33, a worm wheel Ⅱ shaft 34 and a servo controller ⅠM. The servo motor Ⅰ29 is fixedly connected to the middle position of the lower part of the fixed frame 30 of the mounting shell 32, the output shaft of the servo motor Ⅰ29 is fixedly connected to the lower end of the worm 24, the servo controller ⅠM is fixedly connected below the servo motor Ⅰ29, and the input end of the servo controller ⅠM is connected to the output end of the variable fertilizer controller F of the drone D to ensure sensitive control of the speed of the servo motor Ⅰ, and the Hall element Ⅰ28 is fixedly connected to the lower end of the worm 24 to obtain the worm speed in real time; the secondary gear Ⅰ22, the worm wheel Ⅰ23, the worm 24 , worm wheel II 25 and secondary gear II 26 are arranged in sequence from right to left, and the centers of secondary gear I 22, worm wheel I 23, worm wheel II 25 and secondary gear II 26 are on the same straight line, the right side of the worm 24 is meshed with the secondary gear I 22 via the worm wheel I 23; the left side of the worm 24 is meshed with the secondary gear II 26 via the worm wheel II 25; the secondary gear I 22 is fixedly connected to the rear side of the groove wheel shaft II 31, the secondary gear II 26 is fixedly connected to the rear side of the groove wheel shaft I 27, the worm wheel I 23 is fixedly connected to the worm wheel I shaft 33, the worm wheel II 25 is fixedly connected to the worm wheel II shaft 34, the rear ends of the groove wheel shaft I 27 and the groove wheel shaft II 31 are movably hinged to the mounting shell 32, and the rear ends of the worm wheel I shaft 33 and the worm wheel II shaft 34 are movably hinged to the mounting shell 32; and it is ensured that the worm wheel I 23 and the worm wheel II 25, the secondary gear I 22 and the secondary gear II 26 rotate in opposite directions at the same speed during the rotation process.

[0036] like Fig.10 , Fig.11 As shown, the fertilizer spreading transmission mechanism L is composed of a transmission gear Ⅰ17, a transmission gear Ⅱ21, a transmission gear shaft Ⅰ35, a driving gear 36, a Hall element Ⅱ37, a servo motor Ⅱ38, a motor output shaft 39, a transmission gear shaft Ⅱ40 and a servo controller ⅡN. The upper end of the output shaft 39 of the servo motor Ⅱ38 is fixedly connected to the driving gear 36, the servo controller ⅡN is fixedly connected to the bottom of the servo motor Ⅱ38, and the input end of the servo controller ⅡN is connected to the output end of the variable fertilizer controller F of the drone D to ensure sensitive control of the speed of the servo motor Ⅱ. The Hall element Ⅱ37 is fixedly connected to the front end of the motor output shaft 39 so as to obtain the motor output speed in real time; the transmission gear Ⅰ17, the driving gear 36 and the transmission gear Ⅱ21 are arranged and meshed in sequence from right to left; the center of the transmission gear Ⅰ17 is fixedly connected to the lower end of the transmission gear shaft Ⅱ40, and the center of the transmission gear Ⅱ21 is fixedly connected to the lower end of the transmission gear shaft Ⅰ35;

[0037] like Fig.12 As shown, the variable fertilization method of the UAV variable fertilization device of the present invention comprises the following steps:

[0038] 1.1 Obtain the location information of the work site through the global positioning system, and draw the site grid in the description in combination with the geographic information system (GIS);

[0039] 1.2 The variable fertilization expert system C combines soil nutrients and target yield information to obtain the fertilizer amount for each grid and generate a fertilization prescription map;

[0040] 1.3 Obtain the target fertilization amount based on the information of the fertilization prescription map, and import the target fertilization amount information into the UAV fertilization control system B;

[0041] 1.4 When the UAV is working in the field, the UAV fertilization control system B determines the location of the UAV according to the positioning system signal, and combines the fertilization prescription information and the flight speed of the UAV to determine the speed of the servo motor I 29 and the servo motor II 38, and further obtains the speed of the groove wheel and the speed of the spiral fertilizer wheel;

[0042] 1.5 The ultrasonic sensor 15 obtains the real-time fertilizer discharge volume, and transmits the real-time fertilizer discharge volume as a feedback signal to the UAV fertilization control system B. The UAV fertilization control system B adjusts the servo motor speed according to the target fertilizer amount to achieve fertilizer amount adjustment, and finally completes variable fertilization in different operation areas.

Claims

1. An unmanned aerial vehicle variable-rate fertilization device, comprising a mechanical structure part (A), an unmanned aerial vehicle fertilization control system (B) and a variable-rate fertilization expert system (C), wherein the mechanical structure part (A) comprises an unmanned aerial vehicle (D), a battery assembly (E), a variable-rate fertilization controller (F), a support rod assembly (I), a fertilizer discharge component (G), a fertilizer spreading component (H) and a support plate assembly (J), the unmanned aerial vehicle (D) adopts a commercially available six-rotor electric unmanned aerial vehicle, the battery assembly (E) is fixedly connected to the top of the unmanned aerial vehicle (D), the variable-rate fertilization controller (F) is fixedly connected to the middle of the unmanned aerial vehicle (D), and the support rod assembly (I) is fixedly connected to the bottom of the unmanned aerial vehicle (D), characterized in that: The fertilizer discharging component (G) is composed of a fertilizer box cover (1), a fertilizer box (2), a fertilizer discharging port (3), a fertilizer baffle plate I (4), a fertilizer baffle plate II (5), a groove wheel I (6), a groove wheel II (7), a fertilizer box side cover (8), a guide plate (9), a fertilizer transport plate (10) and a fertilizer discharging transmission mechanism (K), wherein the fertilizer discharging transmission mechanism (K) is composed of a secondary gear I (22), a worm wheel I (23), a worm (24), a worm wheel II (25), a secondary gear II (26), a groove wheel rotating shaft I (27), a Hall element I (28), a servo motor I (29), a fixing frame (30), a groove wheel rotating shaft II (31), a mounting shell (32), a worm wheel I rotating shaft (33), a worm wheel II rotating shaft (34) and a servo controller I (M ), the servo motor I (29) is fixedly connected to the middle position of the lower part of the fixing frame (30) of the mounting shell (32), the output shaft of the servo motor I (29) is fixedly connected to the lower end of the worm (24), the servo controller I (M) is fixedly connected below the servo motor I (29), the input end of the servo controller I (M) is connected to the output end of the variable fertilizer controller (F) of the unmanned aerial vehicle (D), and the Hall element I (28) is fixedly connected to the lower end of the worm (24); the secondary gear I (22), the worm wheel I (23), the worm (24), the worm wheel II (25) and the secondary gear II (26) are arranged in sequence from right to left, and the centers of the secondary gear I (22), the worm wheel I (23), the worm wheel II (25) and the secondary gear II (26) are in the same straight line The right side of the worm (24) is meshed with the secondary gear I (22) via the worm wheel I (23); the left side of the worm (24) is meshed with the secondary gear II (26) via the worm wheel II (25); the secondary gear I (22) is fixedly connected to the rear side of the groove wheel shaft II (31), the secondary gear II (26) is fixedly connected to the rear side of the groove wheel shaft I (27), the worm wheel I (23) is fixedly connected to the worm wheel I shaft (33), the worm wheel II (25) is fixedly connected to the worm wheel II shaft (34), the rear ends of the groove wheel shaft I (27) and the groove wheel shaft II (31) are movably hinged to the mounting shell (32), and the rear ends of the worm wheel I shaft (33) and the worm wheel II shaft (34) are movably hinged to the mounting shell (32); and it is ensured that the worm wheel I (23) and the worm wheel II (25) are movably hinged to the mounting shell (32) during the rotation process. ), the secondary gear I (22) and the secondary gear II (26) rotate in opposite directions at the same speed; the fertilizer box cover (1), the fertilizer box (2) and the fertilizer discharge port (3) are arranged and fixedly connected from top to bottom, the center of the fertilizer discharge port (3) coincides with the center of the lower end surface of the fertilizer box (2), the guide plate (9) is an inverted V-shaped structure, the rear end surface of the guide plate (9) is fixedly connected to the front of the rear side plate of the lower part of the fertilizer box (2), and satisfies α≤β≤1.5α, wherein β is the angle between the hypotenuse of the guide plate and the horizontal direction; α is the repose angle of the fertilizer pile, which is generally 30°-40°; the fertilizer baffle plate I (4) and the fertilizer baffle plate II (5) are fixedly connected to the inner side of the left and right side plates of the lower part of the fertilizer box (2) symmetrically, and the angle δ between the center lines of the fertilizer baffle plate I (4) and the fertilizer baffle plate II (5) is greater than (π-2α);The manure conveying plate (10) is conical in structure, and its upper end is fixedly connected to the inner wall of the upper part of the manure box (2). The cone angle θ satisfies 180° - 2β < θ < 180° - β. The diameter d of the blanking port at the lower end of the manure conveying plate (10) satisfies R < d < 2R, where R is the radius of the sprocket I (6) and the sprocket II (7). The distance h between the lower end of the manure conveying plate (10) and the upper end of the diversion plate (9) satisfies 0.7R < h < R. The side cover (8) of the manure box, the sprocket I (6), the sprocket II (7), the manure box (2), and the fertilizer discharging transmission mechanism (K) are arranged in sequence from front to back. The side cover (8) of the manure box is fixedly connected to the front surface of the lower part of the manure box (2) by bolts. The sprocket I (6) and the sprocket II (7) have the same structure, and there are 8 protrusions in the protrusion group (a) and 8 grooves in the groove group (b) on their circumferences, and each protrusion and groove are arranged at intervals. The sprocket I (6) and the sprocket II (7) are symmetrically arranged on the left and right in the lower cavity of the manure box (2). The sprocket I (6) is fixedly connected to the front end of the sprocket rotating shaft I (27) of the fertilizer discharging transmission mechanism (K). The sprocket II (7) is fixedly connected to the front end of the sprocket rotating shaft II (31) of the fertilizer discharging transmission mechanism (K). The sprocket I (6) and the sprocket II (7) rotate in the same direction at the same speed. At the initial moment, the center line of the groove of the sprocket I (6) coincides with the center line of the protrusion of the sprocket II (7) along the horizontal direction. The center distance L between the centers of the sprocket I (6) and the sprocket II (7) satisfies: 3.5R - 1.5r < L < 4R - 2r, where: R is the radius of the sprocket, and r is the distance between the lowest point of the groove and the center of the sprocket. The installation shell (32) of the fertilizer discharging transmission mechanism (K) is fixedly connected to the rear side plate of the lower part of the manure box (2) by bolts. The fertilizer spreading component (H) is composed of a feed inlet (11), a spiral fertilizer discharging wheel I (12), an end cover (13), a discharge outlet (14), an ultrasonic sensor (15), an outer shell (16), a bearing I (18), a bearing II (19), a spiral fertilizer discharging wheel II (20), and a fertilizer spreading transmission mechanism (L). Among them: the fertilizer spreading transmission mechanism (L) is composed of a transmission gear I (17), a transmission gear II (21), a transmission gear shaft I (35), a driving gear (36), a Hall element II (37), a servo motor II (38), a motor output shaft (39), a transmission gear shaft II (40), and a servo controller II (N). The upper end of the output shaft (39) of the servo motor II (38) is fixedly connected to the driving gear (36). The servo controller II (N) is fixedly connected below the servo motor II (38). The input end of the servo controller II (N) is connected to the output end of the variable fertilization controller (F) of the unmanned aerial vehicle (D). The Hall element II (37) is fixedly connected to the front end of the motor output shaft (39). The transmission gear I (17), the driving gear (36), and the transmission gear II (21) are arranged in sequence from right to left and are meshed. The center of the transmission gear I (17) is fixedly connected to the lower end of the transmission gear shaft II (40). The center of the transmission gear II (21) is fixedly connected to the lower end of the transmission gear shaft I (35).The feed port (11) is arranged at the upper front of the outer shell (16), the discharge port (14) is arranged at the lower rear of the outer shell (16), and the discharge port (14) adopts a circular ring-shaped transition to a conical structure from top to bottom, the end cover (13) is fixed to the rear end of the outer shell (16) by bolts, and the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) and is located on the transition line between the circular ring and the conical shape of the inner wall of the discharge port (14); the spiral fertilizer wheel II (20) and the spiral fertilizer wheel I (12) are symmetrically arranged in the left-right direction inside the outer shell (16); the spiral fertilizer wheel I (12) is fixed to the inner wall of the discharge port (14) by bolts; ... by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of the discharge port (14) by bolts; the ultrasonic sensor (15) is fixed to the inner wall of The inner ring of the spiral fertilizer wheel II (20) is fixedly connected to the outer ring of the transmission gear shaft II (40) in the fertilizer spreading transmission mechanism (L), and the rear end of the transmission gear shaft II (40) is movably connected to the right part of the end cover (13) via the bearing I (18); the inner ring of the spiral fertilizer wheel II (20) is fixedly connected to the outer ring of the transmission gear shaft I (35) in the fertilizer spreading transmission mechanism (L), and the rear end of the transmission gear shaft I (35) is movably connected to the left part of the end cover (13) via the bearing II (19); the center distance P between the spiral fertilizer wheel I (12) and the spiral fertilizer wheel II (18) satisfies: R1+r1 / 2≤P≤2R1, where R1 is the spiral blade The variable fertilization expert system (C) is connected to the UAV fertilization control system (B) through wireless data transmission, and the variable fertilization controller (F) of the mechanical structure part (A) is controlled by the UAV fertilization control system (B) and is connected to the variable fertilization controller (F) in the mechanical structure part (A) through wireless data transmission; the outer side of the fertilizer box (2) of the fertilizer discharging component (G) is symmetrically fixed to the rear side of the UAV (D) in the left-right direction, and the outer peripheral surface of the fertilizer discharging port (3) of the fertilizer discharging component (G) is connected to the inner surface of the feeding port (11) of the fertilizer spreading component (H). The circumferential surfaces are fixedly connected, and a gap is left between the lower end of the fertilizer discharge port (3) and the lower edge of the feed port (11) of the fertilizer spreading component (H); the lower end of the outer shell (16) of the fertilizer spreading component (H) contacts the upper end surface of the support plate (42) of the support plate assembly (J), and the servo motor II (38) is placed in the motor mounting frame (43) of the support plate assembly (J), and the discharge port (14) of the fertilizer spreading component (H) is sleeved in the positioning hole (41) of the support plate assembly (J); the left and right lower end surfaces of the support plate (42) of the support plate assembly (J) are respectively fixedly connected to the left and right cross bars of the support rod assembly (I). ; 2. A variable fertilization method based on the UAV variable fertilization device of claim 1, characterized in that: The following steps are involved: 1) Obtain the location information of the work site through the global positioning system and draw the site grid in combination with the geographic information system; 2) The variable fertilization expert system (C) combines soil nutrients and target yield information to obtain the fertilizer amount for each grid and generate a fertilization prescription map; 3) Obtain the target fertilizer amount according to the information of the fertilizer prescription map, and import the target fertilizer amount information into the UAV fertilizer control system (B); 4) When the UAV is working in the field, the UAV fertilization control system (B) determines the location of the UAV according to the positioning system signal, and combines the fertilization prescription information and the flight speed of the UAV to determine the speed of the servo motor I (29) and servo motor II (38), and further obtains the speed of the groove wheel and the speed of the spiral fertilizer wheel; 5) The ultrasonic sensor (15) obtains the real-time fertilizer discharge volume, and transmits the real-time fertilizer discharge volume as a feedback signal to the UAV fertilization control system (B). The UAV fertilization control system (B) adjusts the servo motor speed according to the target fertilizer amount to achieve fertilizer amount adjustment, and finally completes variable fertilizer spreading in different operation areas.

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